1. Field of the Invention
This invention relates to apparatus for securing a wheelchair to a moving vehicle such as a car or van.
2. Prior Art
The difficulty of designing a mechanism for fixing a wheelchair in a moving vehicle has long plagued the industry.
One of the major problems has been designing the locking mechanism so that it meets all government safety standards. This has resulted in devices which are bulky and/or expensive. In some cases, malfunctions of the clamping member can actually break, bend or cause excess stress to the frame structure of the wheelchair. In other cases, a loss of air pressure in the wheelchair tires can result in failure of the restraining member to continue to hold the wheelchair. None of the prior art allows for a locking mechanism which allows 360.degree. manual rotation after the wheelchair has been locked in position. This means that the person sitting in the wheelchair may have difficulty or be unable to change position to see out of a particular window.
The closest known prior art is a device having a flat plate vertically extending from the floor of the vehicle. A hole is provided near one edge of the plate to receive a mechanical latch extending down from a guide support structure attached to the bottom of the wheelchair. The guide support structure has a channel into which the flat plate passes in order to align the latch with the plate opening. However, this device does not allow for rotation of the wheelchair after it has been locked in position and provides for a dangerous vertical plate which could seriously injure anyone who fell on it.